Owls of Central & Northern California Part 2

Some Small Owl Species of Central & Northern California

Owls, of course, come in all sizes and have adjusted themselves to all kinds of habitats, from high mountains to deserts and everything between. They eat all kinds of creatures, from the smallest insects up to fairly good-sized mammals and reptiles. All owls have a special flexible joint in the outer front toe, which swivels to the back when they perch or grasp prey. (Among other raptors, only the Osprey has this flexibility, which helps it maintain a grip on a slippery fish.)

Many people mistake the little Saw-whet and Pygmy Owls for babies of larger species. The “owl” in their minds is the size and shape of the Great Horned and Great Gray. Baby owls of all sizes can be identified by a “fuzzy” look – some of the fluffy baby feathers hang on even as the tougher adult feathers come in. The owls below are fairly common, if seldom seen – there is one other miniature species: The Elf Owl, found in Southern California.

Flammulated Owl

Flammulated Owl (Psiloscops flammeolus), about half the size of the Western Screech in Part 1, otherwise looks much like it – a tiny “horned” owlet. This little creature was once listed as Otus, but along with Western Screech owls, its classification has changed owing to differences in DNA and in certain physiological traits, most notable of which is the voice mechanism that gives this small bird a deceptively deep tenor, like a much larger owl. It also differs from the Screech in having dark brown rather than yellow eyes. The Flammulated typically lives in forested high country, in the Sierra or the Coastal Range, and feeds almost entirely on insects. It is seldom seen, though it is said to be quite common in its territories. Its cry is a kind of “hoo” or “boo,” though during courtship one or the other sex can make an impressively eerie scream. Psiloscops (psilo = single; scops = small owl) is yet another of the many words for a small owl; flammeolus indicates a flame color.

Northern Saw-whet Owl

Northern Saw-whet Owl (Aegolius acadicus) is a bit smaller than the Screech Owl, larger than the Flammulated, and has a charming, heart-shaped face. Owls’ facial disks are composed of stiff small feathers, which the bird can move at will. They surround the eyes and beak, guiding sound to keen ears set, in some species (NOSO one of them), at different heights on the skull. This helps the owl determine sound direction and increases the chances of a successful hunt. The little Saw-whet eats insects and small rodents. A forest lover, it doesn’t often visit our valleys, though in winter in Central California, some may have migrated down from the high country. Its common name refers to its rasping, metallic cry. Aegolius comes from a Greek word indicating a type of owl, and acadicus means “from Acadia,” in Northern Canada, indicating one of the places this owl can be found.

Northern Pygmy Owl

Northern Pygmy Owl (Glaucidium gnoma) This tiny creature, smaller even than the Saw-whet and Flammulated, is nonetheless a fierce hunter, taking on rodents that are comparatively large. It is aided in this by having large, strong feet for its size and a bold attitude. Its tail is relatively longer than that of most other owls, and it has distinct “false eye” spots (called ocelli) on the back of its head. Since it often hunts by day, this coloration may frighten off predators attacking it from above. As evident in the photograph, this owl also has a charming sprinkle of star spots on the front of its head. Its flight is relatively noisy for an owl, and according to naturalist Mark Moore, resembles that of a shrike, with rapid wing beats and rounded wing tips. Glaucidium, too, comes from a Greek word, glaux, for a type of owl, apparently connected to its glaring eyes; gnoma indicates both knowledge and small size.

Burrowing Owl

Burrowing Owl (Athene cunicularia)These long-legged little gnomes of open grasslands and agricultural areas live in colonies, laying their eggs and roosting in abandoned prairie-dog or ground-squirrel burrows, hunting insects and small rodents during the day and early evening. Unlike most owls, they have skinny, nearly featherless legs and small heads, but their large white “eyebrows” over boldly staring eyes and flashy white cravat give them the look of natty little old men in mufti. Their alarm cry is a warbling chitter – they will bob their heads to focus on the danger, then pop down their holes. Like most raptors, the female is a bit larger than the male – but only during the breeding season! The female incubates the eggs and tends the young when newly hatched. The young’s warning cries sound uncannily like a rattlesnake, which surely discourages predators – even snakes, who cruise therodent burrows looking for easy meals. These little owls, once common in California’s Central Valley, are rapidly diminishing in number as human construction paves over the open country and as towns seek to get rid of prairie dog and gopher “cities.” Locally they are thriving on military bases and golf courses, where open areas still exist. Some of these owls bring mammal feces into their burrows, presumably to attract beetles or to “announce” occupancy. The Florida subspecies regularly excavate their own burrows, but the Western ones seem to depend on abandoned burrows, which they clean out by digging with their beaks and kicking loose dirt out with their feet. Their scientific name, “Athene,” refers to the Greek goddess of wisdom and warfare, who is accompanied in many paintings and sculptures by the Little Owl of Europe, whom our burrower resembles. “Cunicularia” is from a medieval Latin word for rabbit holes.